1. Field of the Invention
This invention is directed toward a connector block used in blasting.
2. Description of the Related Art Including Information Disclosed Under CFR xc2xa7xc2xa71.97-1.99
Connector blocks are used in blasting to connect a small detonator to a signal transmission line to form a blasting device. One form of connector block has an elongated body for holding both a detonator and at least one signal line, the detonator held in a position where the explosive end of the detonator is in close proximity to, and preferably contacts, the signal line extending across the explosive end of the detonator. The connector usually has means for trying to prevent movement of the detonator, relative to the connector and to the signal line, once it is mounted in the connector, in order to have the detonator maintain contact with the signal line.
One known form of this connector is in one piece and employs an elongated body member having a U-shaped cross-section. The detonator is placed in the interior of the body member through an open end in the body member with its explosive end in close proximity to, and preferably contacting, at least one signal line held transversely to the detonator at the opposite closed end of the body member. The interior surface of the wall defining the elongated U-shaped body member has retaining ribs for retaining the detonator from both transverse and longitudinal movement. Another known form of connector is initially in one piece and has a closed tubular body member which holds the detonator against lateral movement. This connector has an integral locking member, the locking member severable from the body member and moveable transversely to the body member to securely hold the detonator in place against longitudinal movement. The locking member is initially integral with the body, but separates from the body member when moved to a locking position. An example of such a connector is shown in U.S. Pat. No. 5,499,581, issued Mar. 19, 1996, Daniel P. Sutula, Jr., inventor.
There are disadvantages in using the known connectors however. The connector with a body member of unshaped cross-section, not withstanding the retaining means on the body member, allows the detonator to be too easily moved transversely. This could move the explosive end of the detonator too far from the signal lines making the assembled blasting device inoperative. The connectors are usually printed with information relating to their use. However, the known one-piece connectors are normally made from a plastic material that requires flame treatment to allow the material to be printed on. Flame treatment is an expensive additional manufacturing step and, in an explosive environment, where the connectors are assembled with the detonators and signal lines, could be dangerous. The one-piece connectors can also be more difficult to mold and, when employing a tubular body member, make it more difficult to inspect the molded body member to ensure that the area where the connection is made between the detonator and the signal line is free from flashing from the molding operation. Any flashing could interfere with the proper operation of the blasting device.
It is the purpose of the present invention to provide a connector that is simple to manufacture and that securely holds a detonator mounted in the connector in contact with a signal line. The connector of the present invention prevents movement of the detonator in both the longitudinal and transverse directions relative to the connector body member once it is mounted in place. It is another purpose to provide a connector in which a detonator can be easily loaded into the connector. It is a further purpose of the present invention to provide a connector which can be more easily checked that it is properly molded without flashing. In one embodiment of the invention it is a purpose to provide a connector which can be easily printed on without requiring flame treatment. In this embodiment, the connector has a separate cover which can be made from easily printed material.
The invention provides a connector block having a body member with an elongated, open, base and a connector head at one end. The connector head has a slot extending transversely to the long direction of the base with the slot being just wide enough to clampingly receive one or more signal lines. An opening extends through the head from the base side to the slot for snugly receiving one end of a detonator. Support means on the base are aligned with the opening in the end wall, the support means supporting the detonator while its front end is in the opening contacting the signal lines in the slot. A cover closes the open base with the detonator on the base. The cover and base have cooperating locking means for locking the cover to the base in the closed position. The cover includes separate retainer means cooperating with the detonator to prevent the detonator from both moving rearwardly longitudinally away from the slot and from moving transversely. The cover can be can be an integral part of the body member, connected to the base along one side by a flexible strip. Alternatively, the cover can be a separate member from the body member.
Since the base is open, a person can check that the base has been molded correctly and that there is no flashing in the detonator receiving opening in the connecting head. The open base also allows the base to be easily molded and the detonator to be easily mounted on the base. The cover locks easily and securely to the base and securely holds the detonator against any movement through the retaining means on the cover. If the cover is separate from the body member, it can be made from a material different from the material of the body member which cover material allows printing without the material having to be flame treated. The separate covers allows both the body member and cover to be more easily molded. Using a separate cover allows the covers to be preprinted and stockpiled for use with the body members.
The invention is particularly directed toward a block connector for holding a detonator having an explosive end. The connector has a body member and a cover. The body member has an elongated, open, base and a connector head at one end of the base, the connector head having holding means for holding one or more signal lines. The base has support means for supporting the detonator in an operative position on the body member with its explosive end in at least close proximity with the signal lines held in the connector head. Locking means on the connector lock the cover to the base over the detonator when the detonator is mounted on the support means in the operative position. Retainer means on the cover retain the detonator in the operative position when the cover is locked to the base, the retainer means preventing at least longitudinal movement of the detonator.